To a certain extent the submarine has enabled the torpedo to come into its own. It is not at all an easy task to hit a rapidly moving ship from a platform also ploughing the water at a great rate. Among other things the speed and distance of the opponent have to be taken into consideration, and the missile aimed ahead of the enemy so that it and the target shall arrive at a given point at the same moment. The late Mr Robert Whitehead’s invention, an improvement on that of Commandant Lupuis, of the Austrian Navy, who had sold his patent to the former, was tested by the British Admiralty at Sheerness in 1871. Although extremely crude when compared with its successor of to-day, the sum of £15,000 was paid for the English rights. It was first put to a practical test in the Russo-Turkish War of 1877, when Lieutenant Rozhdestvensky, who afterward suffered defeat at the hands of the Japanese in May 1905, sank a Turkish warship by its means. Viscount Jellicoe has told us that the arrival of the submarine led to certain alterations in strategy. I quote from an interview which the former First Sea Lord granted to a representative of the Associated Press in the spring of 1917. Sir John, as he then was, said: “The most striking feature of the change in our historic naval policy resulting from the illegal use of submarines, and from the fact that the enemy surface ships have been driven from the sea, is that we have been compelled to abandon a definite offensive policy for one which may be called an offensive defensive, since our only active enemy is the submarine engaged in piracy and murder.” Mr Winston Churchill, First Lord of the Admiralty in August 1914, put the matter a little more bluntly. “But for the submarine and the mine.” he wrote, “the British Navy would, at the outset of the war, have been able to force the fighting to an issue on their old battleground—outside the enemy’s ports.” This did not mean that every other type of ship had been rendered obsolete or even obsolescent by the coming of the vessel that can float on or under the waves. Admiral von Capelle, Secretary of State for the German Imperial Navy, told the Main Committee of the Reichstag that the submarine was an “important and effective weapon,” but added that “big battleships are not wholly indispensable. Their construction depends on the procedure of other nations.”[5] For instance, the submarine has emphasized the importance of the torpedo-boat destroyer, which some seamen thought it would supersede. The T.B.D. has more than maintained its own. Not only is it useful for acting independently, fighting its own breed, but as the safeguard of the battleships and battle-cruisers at sea, and also as the keenest weapon against submarines, the naval maid-of-all-work has proved extraordinarily efficient.[6]